1. Field of the Invention
The present invention relates to a pneumatic tire, more particularly to a structure of the tread portion designed for use on rough terrain and provided with specifically configured blocks capable of improving the durability while maintaining braking and cornering performance.
2. Description of the Related Art
In general, pneumatic tires for off-road vehicles have block tread patterns with a plurality of blocks. Typically block tread patterns have a relatively low land ratio which means that the blocks are arranged sparsely as compared with tires designed for on-road use in order to obtain traction, braking and cornering force by offering more deeply engagement between blocks and rough terrain.
As a result, during running, the block is repeatedly subjected to large stress, and damages such as cracks tend to occur. When the tire is used under extremely severe conditions, for example, in a motocross race, chunking that large pieces of rubber break away from a block may occur in the worst case.